Fork lift vehicle



R. REQNSHAW 3,187,841 FORK LIFT VEHICLE 4 Sheets-Sheet 1 June 8, 1965Filed June 20. 1962 June 8, 1965 R. RENSHAW FORK LIFT VEHICLE 4Sheets-Sheet 2 Filed June 20. 1962 INVENTOR. E0567? Hens/242w,

III 1 W 4 Sheets-Sheet 3 Filed June 20, 1962 INVENTOR.

June 8, 1965 R. RENSHAW FORK LIFT VEHICLE 4 Sheets-Sheet 4 Filed June20, 1962 INVENTOR. I 1 201507, [Zens/2am,

/11 BY Z W M United States Patent 3,187,841 FQRK LIFT VEHICLE RobinRenshaw, West Chicago, Ill., assignor to Modern gydranlics, Inc, WestChicago, Ill., a corporation of H1015 Filed June 20, 1962, Ser. No.203,772

11 Claims. (Cl. 187-9) The present invention is directed to a fork liftvehicle and, more particularly, to a lightweight fork lift vehicle whichis propelled or motivated by foot-operated pedals.

Most fork lift trucks now inuse are relatively large, being rated forloads of two thousand pounds and up, and are either electrical orgasoline powered units. The size, weight, and high cost of suchconventional fork lift trucks does not warrant their use above ground orfirst floor levels or where lighter loads are to be transferred betweenpoints which are not spaced considerable distances apart. Suchconventional fork lifttrucks are also not adapted for use where noise isobjectionable and cleanliness is important, as in hospitals,laboratories, food stuff and drug outlets, etc., or where inflammablematerials are stored because of the danger of the machine sparking andcausing explosions, as in chemical manufacturing plants, inflammablematerial industries, etc.

It is, therefore, an important object of the present invention toprovide a new and novel fork lift vehicle which is simple, silent,clean, and efficient in operation, which is relatively inexpensive,compact and lightweight, weighing only about two hundred and fiftypounds while being rated for lifting loads up to five hundred pounds orone thousand pounds, and which is characterized by the absence ofgasoline fumes or electrical operating parts which could cause sparkingand thus be dangerous where inflammable materials are present.

Another important object of the present invention is to provide a newandnovel fork lift vehicle having the foregoing characteristics andwhich is particularly well adapted for use in food stores and foodwholesale outlets, drng houses, laboratories, chemical manufacturingplants, industries marketing inflammable materials, hospitals, etc.

Another important object of the present invention is to provide a newand novel fork lift vehicle having the foregoing features which includesa lightweight frame structure mounted on wheels and having a seat and asteering mechanism, a lifting fork movable in a vertical direction onthe forward end of the frame structure, and footoperated pedals operablyconnectable by chain and sprocket means to certain of the Wheels forpropelling or driving the vehicle.

Another important object of the present invention is to provide a newand novel pedal-propelled fork lift vehicle of the character describedwherein the lifting fork is pivotally mounted on a vertically movablefork carriage for vertical movement therewith and for pivotal movementrelative thereto between a first operable position in which the liftingfork projects forwardly of the front end of the vehicle and a secondposition in which the lifting fork extends rearwardly of thefront end ofthe vehicle, in which second position the over-all length of the vehicleis substantially shortened to increase the maneuverability thereof andto permit the vehicle to fit in a standard size elevator, the relativelightness of the vehicle permitting use of same above a first or groundlevel.

ice

Another important object of the invention is to provide a new and novelpedal-propelled fork lift vehicle of the character described wherein thelifting fork may'be raised and lowered either by a chain and sprocketmechanical connection from the foot-operated pedals or by a hydraulicunit actuated by pump means on the vehicle, which pump means may beeither a hand-operable pump, an electric motor-driven pump, or arotatably drivable pump which is mechanically connectable to thefoot-operated pedals by chain and sprocket means.

i A further object of the present invention is to provide in apedal-propelled fork lift vehicle of the character described, whereinthe lifting fork is either vertically movable mechanically through chainand sprocket means connectable to the foot-operated pedals orhydraulically by a pump which is drivingly connectable through chain andsprocket means to the foot-operated pedals, a manually operable shiftingmechanism whereby the foot-operated pedals may be selectively connectedto the drive wheels fork being shown in its normal forwardly projectingposition in full line and in its rearwardly pivoted position in brokenline and ,with the maximum and minimum height positions of the liftingfork being shown in broken line;

FIG. 2 is a top plan view of the fork lift vehicle of FIG. 1;

FIG. 3 is a rear end elevational view of the fork lift vehicle of FIGS.1 and 2;

FIG. 4 is a perspective view of the foot-pedal drive to the front drivewheels;

FIG. 5 is a partially broken side elevational view of the steeringmechanism for the single rear wheel of the vehicle with certain partsshown in vertical section;

FIG. 6 is a horizontal sectional view taken generally on the line 66 ofFIG. 5;

FIG. 7 is a partially broken enlarged vertical central section takengenerally on the line 7-7 of FIG. 2 through the hydraulic cylinder andpiston unit provided in three forms. of the invention;

FIG. 8 is a front elevational view of the fork carriage;

FIG. 9 is a side elevational view thereof;

FIG. 10 is a top plan view thereof;

FIG. ll is an enlarged scale horizontal sectional "iew taken generallyon the line 11-11 of FIG. 8;

FIG. 12 is an enlarged scale vertical sectional View taken generally onthe line 12-12 of FIG. 8;

FIG. 13 is a side elevational view of one form of the invention whereina manually operable pump is provided for actuating the hydrauliccylinder and piston unit with the basic vehicle structure being shown inbroken line;

FIG. 14 is an enlarged scale central vertical section through themanually operable pump of FIG. 13;

FIG. 15 is a partial side elevational view of a second form of theinvention in which an electric motor-driven pump is provided foractuating the hydraulic cylinder and 3 4 piston unit with the rearportion of the basic vehicle structure being shown in broken line;

FIG. 16 is a schematic diagram for the electric motordriven pump of FIG.

FIG; 17 is a diagrammatic side elevational view of the pedal-drive for athird form of the invention wherein a pump for actuating the. hydrauliccylinder and piston unit is mechanically driven by the foot-operatedpedals;

FIG. 18 is a diagrammatic top plan view of the pedaldrive of FIG. 17; i

FIG. 19 is an enlarged scale vertical sectional view taken generally onthe line 19-19 of FIG. 18;

FIG. 20 is a partially broken perspective view of the shifting mechanismprovided for the pedal-drive of FIGS. 17 and 18;

FIG. 21 is a diagrammatic side elevational view of the pedal-drive for afourth form of the invention wherein the lifting fork is raised andlowered by a mechanical con nection to the foot-operated pedals;

' FIG. 22 is a partially broken rear elevational view taken generally onthe line 22-22 of FIG. 21; and

FIG. 23 is a fragmentary vertical sectional view showing the liftingfork in its normal forwardly projecting position in full line and in itsrearwardly extending position in broken line.

Four embodiments of the pedal-propelled fork lift vehicle of theinvention are illustrated in the drawings. As will be evidenthereinafter, the primary difference between these four embodiments is inthe means provided for moving the lifting fork in a generally verticaldirection. In three forms of the invention the lifting fork is raisedand lowered by a hydraulic cylinder and piston unit which is operablyconnected to either a manually operable pump, an electricmotor-drivenpump,or a rotatably drivable pump which is mechanically connectable tothe foot-operated pedals of the vehicle. In the fourth form oftheinvention, the lifting fork is mechanically raised and lowered by thefoot-operated pedals.

In describing the various forms of the invention, structure which isidentical in two or more of these forms will be identified by the samereference characters for reasons of clarity and convenience. The basicvehicle structure and mechanisms common to all four forms of theinvention will first be described after which each of the four formswill be described in detail.

As best illustrated in FIGS. 1, 2 and 3, the main 'body or framestructure 25 is of a generally elongated narrow hollow channel structurehaving a generally horizontally disposed top wall 26, a bottom wall 27which tapers downwardly from the rear end of the vehicle toward thefront end thereof, and opposite side walls 28. The frame structure 25could, for example, be formed of inch .steel plate. A pair of relativelywidely spaced apart front drive wheels 30 are mounted on the ends of adrive axle 31 extending through an axle housing 32 which is mounted inthe lower front corner of the frame structure 25 in a suitable manner.As best illustrated in FIGS. 1, 3 and 5, a single turnable rear wheel 33is provided at the rear end of the frame structure 25 for supporting andsteering the fork lift vehicle. The rear wheel 33 is mounted in adownwardly opening yoke portion 34 at the lower end of a verticallydisposed shaft 35 which is rotatably mounted in the frame structure 25and has a sleeve bearing 36 and a thrust bearing 37 associatedtherewith. The front drive wheels 30 and the rear turnable wheel 33 maybe provided with either solid or pneumatic rubber tires. A hollowbox-like container structure 38 is secured, as by welding, on the framestructure 25 at the rear end thereof for a purpose which will bedescribed hereinafter and an adjustableseat 39 is mounted thereon.

As best illustrated in FIGS. 1 and 4,. foot-operated pedals 40, similarto those associated with bicycles and operable by a person sitting inthe seat 39, are secured on the opposite ends of a pedal shaft 41 whichis rotatably 4 mounted in the frame structure 25 in a suitable manner.The front wheel drive axle 31 is provided with a commercial differentialunit 43 (FIG. 4) having a driven sprocket 44 secured thereon whereby toprovide a positive drive for both the front wheels 30. In the form ofthe invention shown in FIGS. 1-4, a drive sprocket 45 is mounted on thepedal shaft 41 inwardly of the frame structure 25 with a sprocket chain46 extending about the drive sprocket 45 and the driven sprocket 44associated with the drive axle 31 whereby to provide a vehicle which ispedal-propelled forwardly or rearwardly. An adjustment idler sprocket 47(FIG. 4) for the sprocket chain 46 may also be provided.

The steering mechanism for turning the rear wheel 33 to steer thevehicle may best be described with reference to FIGS. 1, 5 and 6. Anupstanding steering shaft housing 49 is mounted on the top wall 26 ofthe frame structure 25 forwardly of the seat 39 and at a slight rearwardangle for the convenience of a person sitting in the seat 39. A jointedsteering shaft 50 extends through the housing 49 with the upper endthereof extending through a bearing 51 mounted in the upper end of thesteering shaft housing 49 and having a steering wheel 52 mountedthereon. A lower vertically disposed portion of the steering shaft 50 ismounted in the frame structure 25 with a sleeve bearing 53 associatedtherewith. The steering shaft 50 is characterized by upper and lowersections connected by a standard universal joint 54 whereby the uppersection may be accommodated in the slightly rearwardly tilted steeringshaft housing 49.

A sprocket 56 is secured on the lower end of the steering shaft 59 witha sprocket 57 being secured on the rear wheel shaft 35 rearwardly of thesteering shaft sprocket '56 and an adjustable idler sprocket S-Sbeingmounted in the frame structure 25 forwardly of the steering shaftsprocket 56. As best illustrated in FIG. 6, a sprocket chain 59 extendsabout the rear wheel sprocket 5'7 and the idler sprocket 58 and aboutone side of the steering shaft sprocket 56 in a manner such that whenthe steering wheel 52 is turned to the right the vehicle will turn tothe right and vice versa.

A generally vertically disposed guide and support structure 61 issecured at its lower end, as by welding, to the front end'of the framestructure 25 with the major portion of the guide and support structure61 projecting thereabove. As best illustrated in FIGS. 3 and 10, theguide and support structure 61 is characterized by a pair of laterallyspaced apart inwardly opening U-shaped steel channel members 62 whichare interconnected at their upper and lower ends by plate members 63 and64, respectively. A fork carriage 66, best illustrated in FIGS. 8,

9, l0 and 11, is mounted on the guide and support structure 61 forgenerally vertical movement relative thereto. The fork carriage 66 ischaracterized by a vertically extending rearwardly opening U-shapedbracket 67 which is disposed between the channel members 62 of the guideand support structure 61 with each rearwardly extending side portion 68thereof having a pair of vertically spaced cast iron rollers 69rotatably mounted thereon with each pair of rollers 69 being confinedfor rolling engagement in one of the U-shaped channel members 62 of theguide and support structure 61. As best illustrated in the detail viewof FIG. 11, each roller 69 is rotatably mounted on the outer end of ahardened pin 70 by means of a bushing or roller bearings 71 with theopposite inner end of the pin 74) being retained by a set screw 72 in ahub 73 which is secured, as by welding, on the inner surface of therearwardly projecting side portion 68 of the U-shaped bracket 67. Asteel washer 74 is provided on each pin 70 between the roller69 and theouter surface of the rearwardly projecting side portion 68 of thebracket 67. The bracket 67 of the fork carriage 66 could also beslidably mounted between the U-shaped channel members 62.

The fork carriage 66 is further characterized by a pair of vertically,spaced horizontally disposed rearwardly opening channel members 76 ofsubstantial lateral width which are secured, as by welding, to the frontsurface of a transversely extending front portion 77 of the U-shapedbracket 67. The opposite ends of the channel members '76 are providedwith side plates 78 which project above the uppermost channel member 76with the upper projecting portions thereof being provided withhorizontally aligned bores 79. A rod 80 (FIG. 2) extends through thealigned bores '79 in the side plates 78 and. is secured therein by nuts81 threadedly mounted on the opposite ends thereof. A lifting fork 82defined by a pair of rightangular lifting members is mounted on the rod80 for generally vertical movement with the fork carriage 66. In theirnormal operable positions, each right-angular lifting member ischaracterized by a forwardly directed load supporting portion 83, avertically disposed portion 84 extending upwardly from the rear endthereof and dis posed against the front surfaces of the channel members76, and by a rearwardly extending collar portion 85 at the upper end ofthe vertically disposed portion 84, which collar portion 34 is rotatablyand slidably mounted on the rod Sti whereby the lifting fork 82 is bothvertically movable with the fork carriage 66 and rearwardly pivotablerelative thereto about the rod 80. g

In the first three forms of the fork lift vehicle to be describedherein, the fork carriage 66 and the lifting fork 82 are verticallymovable by hydraulic means. As best illustrated in FIGS. 1 and 7, agenerally vertically disposed hydraulic cylinder 86 having its lower endclosed by a iounting block plug 87 is mounted on the lower plate member64 of the guide and support structure 61 between the U-shaped channelmembers 62 thereof. A piston 88 in the cylinder $6 is secured on thelower end of a piston rod $9 by a retaining ring ht The piston rod 39projects upwardly out of the cylinder 86 through a bronze bushing *1which is mounted in the upper end of the cylinder 3d and which has apacking seal 92 and an O-ring seal 93 associated therewith. A piston rodwiper 94 is provided at the upper end of the bushing 91.

The piston rod 219 is provided at its upper end with an upwardly openingyoke portion 95 in which a sprocket 96 is supported for rotation about ahorizontally disposed transversely extending pin 97. A sprocket chain 99extending over the sprocket as has the lower end of the rearwardlydisposed run thereof secured to the frame structure 25, as at 1959, andthe lower end of the forwardly disposed run thereof secured to the upperend ofthe fork carriage 66 by a connection between a joining linkthereof and a joining block 1412 (FIG. 12) which is welded to the rearsurface of the transversely extending front portion 77 of the bracket67. j

A passage 103 formed in the mounting block plug 87 opens at one end tothe lower end of the cylinder 86 with its opposite end being adapted toreceive one end of a fluid conduit 104 which is connectable at itsopposite end to a source of hydraulic fluid pressure, such as pumpmeans. When hydraulic fluid under pressure is directed into the lowerend of the hydraulic cylinder 86, the piston 85 and the sprocket 96 onthe upper end of the piston rod 89 are moved upwardly relative to thecylinder 86 with the fork carriage 66 and the lifting fork 82 thus beingpulled upwardly in a generally vertical direction by the sprocket chain99 in an obvious manner. With the chain 9% and sprocket 95 arrangementdescribed herein, the fork carriage 66 and the lifting fork 82 aremovable upwardly at twice the rate and twice the distance of the upwardmovement of the piston 38 in the cylinder 86. When pressure is relievedfrom the cylinder 86, the piston 88 and the sprocket are permitted tomove downwardly whereby to lower the fork carriage 66 and the liftingfork '32. j

The first specific form of the fork liftvehicle of the in vention inwhich hydraulic fluid under pressure is directed to the hydrauliccylinder 86 by means of a manually operable pump may best be describedwith reference to 6 FIGS. 13 and 14. In the fork lift vehicle of FIG.13, the vehicle is propelled by a direct pedal drive through the chain46 and the sprockets 45 and 44. A standard hydraulic hand-operable pump106 of a known type is mounted on the side of the box-like container 38in a position such that it is readily operable bya person sitting in theseat 39. One manually operable pump 106 which is suitable for use is thecommercial model manufactured by Templeton, Kenley & Co. of Broadview,

Illinois, and illustrated in detail in FIG. 14. This pump 1% provides ahigh volume, low pressure output for raising the lifting fork 82 rapidlyunder no load conditions and automatically provides a high pressure, lowvolume output during an actual load lifting operation. As the details ofthe manually operable pump 106 form no part of the invention, thestructure and operation thereof will merely be described herein in abrief manner. The pump 1% includes a hydraulic fluid reservoir portion107, an inlet-outlet port 198 to which the fluid conduit 104 isconnectable, and a reciprocal piston 109 having a large diameter highvolume, low pressure portion 110 and a smaller diameter low volume, highpressure portion 111. The larger diameter piston portion has associatedtherewith a fluid passage connection 112 to the fluid reservoir 187 withan adjustable by-pass valve 113 being provided therein, which valve 113is normally set at relatively low pressures, and a fluid pass-ageconnection 114 to the inlet-outlet port 10% with a ball valvearrangement 115 of known type being provided therein. The smallerdiameter piston portion 111 has associated therewith a fluid passageconnection 116 to the fluid reservoir 1G7 and a fluid passage connection117 to the inlet-outlet port 108 with a ball valve arrangement 118 ofknown type being provided therein. The pump 1% is also provided with amanually operable release valve 119 associated with a fluid-returnpassage connection 120 between the inletoutlet port 1618 and the fluidreservoir 1%37 and with a high pressure safety by-pass valve arrangementlfzl. The piston 109 is reciprocal by means of a pivotally mountedmanually pumpable handle 122 which is operably connected to the piston109 in a known manner and which is readily operable by a person sittingin the seat 39.

When the pump 106 is actuated under a no load condition, both pistonportions 110 and 111 are operable to provide high volume, low pressureoutput. Under loadlifting conditions, the larger diameter piston portion119 s automatically by-passed at relatively low pressures, for instance200 p.s.i., by the by-pass valve 113, whereby only the smaller diameterpiston portion 111 is operable to provide high pressure, low volumeoutput. To lower the fork carriage 66 and the lifting fork 82, therelease valve 119 is manually opened to relieve the pressure in thehydraulic cylinder 86 in an obvious manner.

The second form of the fork lift vehicle of the invention in whichhydraulic fluid under pressure is directed to the hydraulic cylinder 86by an electric motor-driven pump may best be described with reference toFIGS. 15. and 16. It should first be noted that in this second form ofthe invention, the fork lift vehicleds propelled by the same directchain and sprocket drive between the footoperated pedals and the frontdrive axle as previously described for the first form of the inventionshown in FIG. 13. As illustrated in FIG. 15, a DC. electric motor 125and a standard commercial hydraulic pump 126 includmg a built-inhydraulic fluid reservoir portion 127 are mounted on one side of thebox-like compartment 38 convenient to a person sitting in the seat 39.Storage batteries (not shown) electrically connected to the DC. electricmotor 125 are preferably housed in the box-like compartment 3% beneaththe seat 39 whereby they aid in counterbalancinga load on the liftingfork 82 at the forward end of the vehicle.

A schematic diagram of the electrical and hydraulic system for this formof the invention, the details of which form no part of the invention, isillustrated in FIG. 16.

7 As illustrated, the electric motor 125 is drivingly connected to thehydraulic pump 125 which has a fluid inlet connection to the hydraulicfluid reservoir 127 and a fluid outlet connection, including a checkvalve 123, connectable to the fluid conduit 1 34 which is connected atits opposite end to the hydraulic cylinder 86. The system furtherincludes an adjustable safety pressure relief valve 13%) and acam-openable release valve 131 for relieving the pressure in the liftingcylinder 86. A two-way control lever 132, positioned for convenientoperation by a person in the seat 39, when moved in one directionactuates a starter switch 133 for the electric motor 125 whereby todrive the pump 126 and direct fluid under pressure to the hydrauliccylinder 86 to raise the lifting fork 82. When the control lever 132 isreleased, it immediately returns to its normal neutral position wherebyto stop the motor 125 and the pump 126 with the lifting fork 82 beingretained in .a raised position. When the control lever 132 is moved inthe opposite direction, the release valve [131 is opened by cam meansassociated with the control lever 132 whereby to relieve the pressure inthe hydraulic cylinder 86 and thereby lower the lifting fork 82.

The third form of the fork lift vehicle of the invention in whichhydraulic fluid under pressure is directed to the hydraulic liftingcylinder 86 by a rotatably drivable hydraulic pump which is mechanicallyconnectable to the foot-operated pedals 48 may best be described withreference to FIGS. 17, 18, 19 and 20, FIGS. 17 and 18 being somewhatdiagrammatic in nature for purposes of clarity. As best illustrated inFIGS. 18 and 19, the pedal shaft 41 is provided with a longitudinallyextending keyway 135 with a pedal gear 136 being keyed thereon in theusual manner and adapted for axial movement between opposite limitpositions relative to the pedal shaft 41. In one limit position thepedal gear 136 is meshed in driving engagement with a driven gear 137and in the opposite limit position the pedal gear 136 is meshed indriving engagement with a driven gear 138. The sprocket chain 46 whichextends about the sprocket 44 associated with the front wheel drive axle3-1 also extends, in this third form of the invention, about a sprocket139 which is mounted on a shaft 141 for rotation with the driven gear137 whereby to provide a direct pedal drive to the front wheels 31) whenthe pedal .gear 136 is meshed in driving engagement with the driven gear137.

A sprocket 142 is mounted on a shaft 143 for rotation with the drivengear 138 when the pedal gear 136 is meshed in driving engagementtherewith. A standard hydraulically drivable hydraulic pump 144 of knowntype, such as a piston pump, and having a hydraulic fluid reservoir 145associated therewith has a sprocket 146 mounted on a drive shaft 147thereof. The pump 144 has an inlet-outlet port (not shown) which isconnectable to the fluid conduit 104 which is connected at its oppositeend to the hydraulic lifting cylinder 86. A sprocket chain 148 extendsabout the sprocket 142 associated with the driven gear 138 and about thesprocket 146 associated with the pump 144 whereby the pump 144 isactuated to deliver hydraulic fluid under pressure through the fluidconduit 104 to the hydraulic cylinder 86 when the pedal gear 136 ismeshed in driving engagement with the driven gear 138 to raise the forkcarriage 66 and the lifting fork 82. The pump 144 is provided with astandard manually operable release valve (not shown) for relieving thepressure in the cylinder 86 to lower the fork carriage 66 and thelifting fork 82.

It is noted, as shown in FIG. 18, that the pedal gear 136 may be axiallypositioned in a centered position be tween the two limit positions, inwhich centered position the pedal gear 136 is meshed in drivingengagement with both the driven gears 137 and 138, thus permitting thelifting fork 82 to be raised while the fork lift vehicle is beingpropelled. Provision is made for selectively shifting the pedal gear 136between its centered and opposite limit positions by a shiftingmechanism which is best illustrated in FIGS. 18, 19 and 20. The shiftingmechanism includes a vertically disposed shaft 150 which is mountedadjacent the steering shaft housing 49 for pivoting movement about itslongitudinal axis. The upper end of the shaft 151 is rotatably mountedin a bracket 151 attached to the steering shaft housing 49 and the lowerend of the shaft 151? has a reduced-in-diameter portion 153 which isrotatably mounted in a bore 154 formed in the top wall 26 of the framestructure 25. A laterally extending arm 1% is rigidly secured to thelower portion of the shaft 151), as by welding, and has a downwardlybent-outer end portion 157 on the lower end of which a hardened steelroller 158 is rotatably mounted in a suitable manner. The roller 158 isreceived in an annular groove 159 formed in one end of the pedal gear136 whereby pivoting movement of the vertical shaft 1511 about itslongitudinal axis serves to shift the pedal gear 136 between itscentered and opposite limit positions. A laterally extending gearshifting lever 168 is secured to the upper portion of the shaft 159 forpivoting same.

The fourth form of the fork lift vehicle of the invention in which thefork carriage 6d and the lifting fork 82 are raised and lowered by thefoot-operated pedals 41 through a direct mechanical connection may bestbe described with reference to- FIGS. 21 and 22. This fourth form of theinvention is identical in certain aspects to the third form of theinvention illustrated in FIGS. 17 and 18 and incorporates the same gearshifting mechanism illustrated in FIGS. 19 and 20. As illustrated inFIG. 21, the pedal shaft 41 is provided with the pedal gear 136, whichis axially shiftable selectively between a centered and opposite limitpositions by the previously described gear shifting mechanism, wherebyto provide a direct mechanical drive to the sprocket 44 associated withthe front wheel drive axle 31 through the driven gear 137, the sprocket139 and the sprocket chain 46, as in the previously described third formof the invention. This form of the invention further incorporates thedriven gear 138, the sprocket 142 associated therewith, and the sprocketchain 148 which extends about the sprocket 142, the driven gear 138being adapted to be selectively meshed in driving engagement with thepedal gear 136.

In this fourth form of the invention, a pair of horizontal transverselyextending shafts 162 and 163 are mounted at the upper and lower ends,respectively, of the generally vertically disposed guide and supportstructure 61 with upper and lower sprockets 164 and 165, respectively,being rotatably mounted thereon approximately midway between the sidechannel members 62 of the guide and support structure 61. An endlesssprocket chain 11% extends about the upper and lower sprockets 164 and165 with the fork carriage 66 being securely attached to a link or linkson the forwardly disposed run thereof for raising and lowering movementtherewith. A drive sprocket 167 is mounted on the lower shaft 163 andhas a sprocket chain 168 extending about the same and about a sprocket169 on an output shaft of a commercial reduction gear box 178 of knowntype. The sprocket chain 148 which extends about the sprocket 142associated with the driven gear 138 also extends about a sprocket 172 onan input shaft of the gear box 178, whereby when the pedal gear 136 ismeshed in driving engagement with the driven gear 138, the drivesprocket 167 for raising and lowering the lifting fork 82 ismechanically connected to the footoperated pedals 40 through the gearreduction box 170 and the aforementioned chain and sprocket drivearrangements. It is noted that the pedal gear 136 may be axially shiftedby the shifting mechanism into either of its limit positions for eitherraising and lowering the lifting fork 82 or propelling the vehicleseparately or into its centered position in which it is meshed indriving engagement with both the driven gears 137 and 138 whereby topermit raising and lowering the lifting fork 82 while the vehicle isbeing propelled.

It is noted that in all four forms of the fork lift vehicle of theinvention described herein, the vehicle may be propelled and the liftingfork 82 raised and lowered either as separate operations or assimultaneous operations, as desired. It is further noted that in allfour forms of the invention, the hollow box-like compartment 38 beneaththe seat 39 is intended to be used for adding weight at the rear end ofthe vehicle as required for counterbalancing a load on the forwardlyprojecting lifting fork 82. It is still further noted that in all fourforms of the invention, all of the chain drives and all of the hydraulicfiuid conduits are disposed within the hollow channehshaped framestructure 25, which feature is important from a standpoint of safety andalso results in the fork lift vehicles having a neat clean appearance.

As a result of the manner in which the right-angular members definingthe lifting fork 82 are mounted on the rod 80, it is noted that same arefreely laterally adjustable thereon whereby the lifting fork 82 isreadily adjustable as to width. Of further interest are the uppermostand lowermost lifting positions of the lifting fork 82 as indi cated inbroken line in FIG. 1.

With the right-angular members defining the lifting fork 32 beingpivotally mounted by their collar portions 85 on the rod 8 3, thelifting fork 82 may be pivoted upwardly and rearwardly into the positionindicated in broken line in FIGS. 1 and 23 whereby to substantiallyshorten the over-all length of the vehicle for greater maneuverabilitywhen the lifting fork 82 is not required. This feature, for instance,permits fitting the fork lift vehicle into a small standard elevator formovement between fioor levels. As illustrated in FIG. 23, a transverselyextending stop member 175 may be provided on the fork carriage 66 tosupport the rearwardly turned lifting fork 82 in a horizontal positionso that a load may be supported thereon rearwardly of the guide andsupport structure 61.

It will be understood that certain additional modifications may be madein the construction or arrangement of the fork lift vehicles disclosedherein without departing from the spirit and scope of the invention asdefined in the appended claims.

I claim:

1. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on wheels and characterized by aseat and means for steering the vehicle, a lifting fork mounted on thefront end of the frame structure for movement in a generally verticaldirection relative thereto, and foot-operated pedals operable from saidseat and adapted to be selectively connected mechanically to certain ofsaid wheels through chain and sprocket means for propelling the vehicleand to said lifting fork through chain and sprocket means for raisingand lowering said lifting fork.

2. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on wheels and characterized by aseat and means for steering the vehicle, a generally vertically disposedsupport and guide structure mounted on the forward end of the framestructure, a fork carriage slidably mounted on said vertically disposedsupport and guide structure for vertical movement relative thereto,first chain and sprocket means associated with said support and guidestructure with said chain being vertically movable relative thereto,means connecting said fork carriage to a portion of said chain forvertical movement therewith, a forwardly projecting lifting fork mountedon said fork carriage for vertical movement therewith, and foot-operatedpedal means operable from said seat and mechanically connectable throughsecond and third chain and sprocket means, respectively, to said firstchain and sprocket means for raising and lowering said fork carriage andto certain of said wheels for propolling the vehicle.

3. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on a pair of front drive wheelsand a third turnable rear wheel and characterized by a seat and meansconnected to said rear wheel for steering the vehicle, a generallyvertically disposed channel structure mounted on the forward end of saidframe structure, a fork carriage having rollers confined in saidvertically disposed channel structure and adapted for vertical movementrelative thereto, a pair of sprockets mounted on said verticallydisposed channel structure at the upper and lower ends thereof forrotation about generally vertically aligned horizontal axes, acontinuous chain extending about said pair of sprockets, meansconnecting said fork carriage to a forwardly disposed run of said chainfor vertical movement therewith, a forwardly projecting lifting forkmounted on said fork carriage for vertical movement therewith, andfoot-operated pedals operable from said seat and selectively connectablemechanically to said pair of front drive wheels through chain andsprocket means for propelling the vehicle and to said lower sprocketthrough separate chain and sprocket means for raising and lowering saidlifting fork.

4. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on wheels and characterized by aseat and means for steering the vehicle, a generally vertically disposedsupport and guide structure mounted on the forward end of the framestructure, a fork carriage slidably mounted on said vertically disposedsupport and guide structure for vertical movement relative thereto,first chain and sprocket means associated with said support and guidestructure with said chain being vertically movable relative thereto,means connecting said fork carriage to a portion of said chain forvertical movement therewith, foot-operated pedal means operable fromsaid seat and mechanically connectable through second and third chainand sprocket means, respectively, to said first chain and sprocket meansfor raising and lowering said fork carriage and to certain of saidwheels for propelling the vehicle, and a forwardly projecting liftingfork pivo-tally mounted on said fork carriage for vertical movementtherewith and for pivoting movement about a horizontal axis relativethereto from said forwardly projecting position to a position whereinsaid lifting fork projects rearwardly of the front end of the vehicle,in which position the over-all length of the vehicle is substantiallyshortened.

5. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on wheels and characterized by aseat and means for steering the vehicle, a lifting fork mounted on thefront end of the frame structure for movement in a generally verticaldirection relative thereto, foot-operated pedals operable from said seatand connectable mechanically to certain of said wheels through chain andsprocket means for propelling the vehicle and to said lifting forkthrough chain and sprocket means for raising and lowering said liftingfork, and a manually operable shifting device for selectively connectingsaid foot-operated pedals to said wheels and to said lifting forkseparately or to both said wheels and lifting fork simultaneously.

6. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on wheels and characterized by aseat and means for steering the vehicle, a generally vertically disposedsupport and guide structure mounted on the forward end of the framestructure, a fork carriage slidably mounted on said vertically disposedsupport and guide structure for vertical movement relative thereto,first chain and sprocket means associated with said support and guidestructure with said chain being vertically movable relative thereto,means connecting said fork carriage to a portion of said chain forvertical movement therewith, a forwardly projecting lifting fork mountedon said fork carriage for vertical movement therewith, foot-operatedpedal means operable from said seat and mechanically connectable throughsecond and third chain and sprocket means, respectively, to said firstchain and sprocket means for raising and lowering said l; l forkcarriage and to certain of said wheels for propelling the vehicle, and amanually operable shifting device for selectively connecting saidfoot-operated pedal means to said second and third chain and sprocketmeans separately or to .both said second and third chain sprocket meanssimultaneously.

7. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on a pair of front drive wheelsand a third turnable rear wheel and characterized by a seat and meansconnected to said rear wheel for steering the vehicle, a generallyvertically disposed channel structure mounted on the forward end of saidframe structure, a fork carriage having rollers confined in saidvertically disposed channel structure and adapted for vertical movementrelative thereto, a pair of sprockets mounted on said verticallydisposed channel structure at the upper and lower ends thereof forrotation about generally vertically aligned horizontal axes, acontinuous chain extending about said pair of sprockets, meansconnecting said fork carriage to a forwardly disposed run of said chainfor vertical movement therewith, a forwardly projecting lifting forkpivotally mounted on said fork carriage for vertical movement therewithand for pivoting movement relative thereto into a rearwardly projectingposition whereby to shorten the over-all length of the vehicle,foot-operated pedals operable from said seat and connectablemechanically to said pair of front drive wheels through chain andsprocket means for propelling the vehicle and to said lower sprocketthrough separate chain and sprocket means and a reduction gear box forraising and lowering said lifting fork, and a manually operable shiftingdevice disposed adjacent said seat for selectively connecting saidfoot-operated pedals to said drive wheels and to said lower sprocketseparately for propelling the vehicle and for raising and lowering thelifting fork, respectively, and to both said drive wheels and said lowersprocket simultaneously for vertically mov ing said lifting fork duringforward or rearwad movement of the vehicle.

3. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on a pair of front drive wheelsand a third turnable rear wheel and characterized by a seat and meansconnected to said rear wheel for steering the vehicle, a generallyvertically disposed channel st-ructure mounted on the forward end ofsaid frame structure, a fork carriage having rollers conlined in saidvertically disposed channel structure and adapted for vertical movementrelative thereto, a vertically disposed hydraulic cylinder and pistonunit mounted on the lower portion of said channel structure and hav inga sprocket mounted on the upper projecting end of a piston rod thereof,a chain extending over said sprocket with its depending rear end securedto said frame structure and with its depending front end connected tosaid fork carriage whereby upward movement of said piston results inupward movement of said fork carriage relative to said verticallydisposed channel structure, a forwardly projecting lifting fork mountedon said fork carriage for vertical movement therewith, a rotatablydrivable pump on said frame structure for actuating said hydrauliccylinder and piston unit to move said piston rod and thus said liftingfork upwardly, and foot-operated pedal means operable from said seat andselectively COIll'lfiCifilblE through separate chain and sprocket meanssimultaneously and separately to said rotatably drivable pump and tosaid pair of drive wheels whereby to permit moving said lifting fork ina vertical direction while propelling the vehicle, moving said liftingfork in a vertical direction while the vehicle is standing still, andpropelling the vehicle with said lifting fork remaining in a desiredposition.

9. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on a pair of front drive wheelsand a third turnable rear wheel and characterized by a seat and meansconnected to said rear wheel for steering the vehicle, a lifting forkmounted on the front end of the frame structure for linear movement in agenerall vertical direction relative to the front end of the framestructure, a hydraulic cylinder and piston device mounted on said framestructure and operably connected for raising and lowering said liftingfork, pump means mounted on said frame structure and operably connectedto said hydraulic cylinder and piston device, foot-operated pedalsoperable from said seat and connecta-ble mechanically through chain andsprocket means to said pair of front drive wheels for propelling thevehicle and to said pump means for operating same whereby to actuatesaid hydraulic cylinder and piston device to raise and lower saidlifting fork, and a manually operable shifting device for selectivelyconnecting said foot-operated pedals to said wheels and to said pumpmeans separately or to both said wheels and said pump means simultane'ously.

19. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on a pair of front drive wheelsand a third turnable rear wheel and characterized by a seat and meansconnected to said rear wheel for steering the vehicle, a generallyvertically disposed support and guide structure mounted on the forwardend of said frame structure, a fork carriage slidably mounted on saidsupport and guide structure for vertical movement relative thereto,first chain and sprocket means associated with said support and guidestructure, hydraulically actuated means operable when actuated to causevertical movement of a portion of said chain relative to said supportand guide structure, means connecting said fork carriage to said chainportion for vertical movement therewith, a forwardly projecting liftingfork mounted on said fork carriage for vertical movement therewith,rotatably driven pump means hydraulically connected to saidhydraulically actuated means, foot-operated pedals operable from saidseat and connectable mechanically to said pair of front drive wheelsthrough second chain and sprocket means for propelling the vehicle andto said pump means through third chain and sprocket means for rotatablydriving same to raise said lifting fork, and a manually operableshifting device disposed adjacent said seat for selectively connectingsaid footoperated pedals to said wheels and to said pump meansseparately or to both said wheels and said pump means simultaneously.

11. A relatively lightweight fork lift vehicle comprising, incombination, a frame structure mounted on a pair of front drive wheelsand a third turnable rear wheel and characterized by a seat and meansconnected to said rear wheel for steering the vehicle, a generallyvertically disposed channel structure mounted on the forward end of saidframe structure, a fork carriage having rollers confined in saidvertically disposed channel structure and adapted for vertical movementrelative thereto, a vertically disposed hydraulic cylinder and pistonunit mounted on the lower portion of said channel structure and having asprocket mounted on the upper projecting end of a piston rod thereof, achain extending over said sprocket with its depending rear end securedto said frame structure and with its depending front end connected tosaid fork carriage whereby upward movement of said piston results inupward movement of said fork carriage relative to said verticallydisposed channel structure, a forwardly projecting lifting fork mountedon said fork carriage for vertical movement therewith, a rotatablydrivable pump on said frame structure for actuating said hydrauliccylinder and piston unit to move said piston rod and thus said liftingfork upwardly, foot-operated pedal means operable from said seat andselectively mechanically connectable simultaneously and separately tosaid rotatably drivable pump and to said pair of drive wheels whereby topermit moving said lifting fork in a vertical direction while propellingthe vehicle, moving said lifting fork in a vertical direction while thevehicle is standing still, and propelling the vehicle with said liftingfork in a desired position, and a manually operable shifting devicedisposed adjacent said seat for selectively 2,529,749 11/50 Wade et a1214-392 connecting said foot-operated pedals through separate 2, 61,5767/51 Johnson 187-9 chain and sprocket means to both said drive Wheelsand 2,709,015 5/55 Sasgen et X said pump simultaneously and to saiddrive Wheels and 2,910,203 10/ 59 Todd -67 said pump separately, 52,919,759 1/60 W h ely 80-53 FOREIGN PATENTS R f C't db th E r e erences1e y e xamlne 1,164,709 5/58, France UNITED STATES PATENTS 1,229,1133/60 France. 1,109,424 9/14 Kiefer 280-261 10 615,281 1/49 GreatBritain. 1,676,449 7/28 Lederer 18711 X 7 241 7 5 1 Weiss 1 7 9 SAMUELF. COLEMAN, Primary Examiner.

2,395,345 2/46 Schreck 137-9 ANDRES H. NIELSEN, Examiner.

1. A RELATIVELY LIGHTWEIGHT FORK LIFT VEHICLE COMPRISING, INCOMBINATION, A FRAME STRUCTURE MOUNTED ON WHEELS AND CHARACTERIZED BY ASEAT AND MEANS FOR STEERING THE VEHICLE, A LIFTING FORK MOUNTED ON THEFRONT END OF THE FRAME STRUCTURE FOR MOVEMENT IN A GENERALLY VERTICALDIRECTION RELATIVE THERETO, AND FOOT-OPERATED PEDALS OPERABLE FROM SAIDSEAT AND ADAPTED TO BE SELECTIVELY CONNECTED MECHANICALLY TO CERTAIN OFSAID WHEELS THROUGH CHAIN AND SPROCKET MEANS FOR PROPELLING THE VEHICLEAND TO SAID LIFTING FORK THROUGH CHAIN AND SPROCKET MEANS FOR RAISINGAND LOWERING SAID LIFTING FORK.